diff options
Diffstat (limited to 'mfbt/SHA1.cpp')
| -rw-r--r-- | mfbt/SHA1.cpp | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/mfbt/SHA1.cpp b/mfbt/SHA1.cpp new file mode 100644 index 0000000..ce9dfc2 --- /dev/null +++ b/mfbt/SHA1.cpp @@ -0,0 +1,342 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include <string.h> +#include "mozilla/SHA1.h" +#include "mozilla/Assertions.h" + +// FIXME: We should probably create a more complete mfbt/Endian.h. This assumes +// that any compiler that doesn't define these macros is little endian. +#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +#define MOZ_IS_LITTLE_ENDIAN +#endif +#else +#define MOZ_IS_LITTLE_ENDIAN +#endif + +using namespace mozilla; + +static inline uint32_t SHA_ROTL(uint32_t t, uint32_t n) +{ + return ((t << n) | (t >> (32 - n))); +} + +#ifdef MOZ_IS_LITTLE_ENDIAN +static inline unsigned SHA_HTONL(unsigned x) { + const unsigned int mask = 0x00FF00FF; + x = (x << 16) | (x >> 16); + return ((x & mask) << 8) | ((x >> 8) & mask); +} +#else +static inline unsigned SHA_HTONL(unsigned x) { + return x; +} +#endif + +static void shaCompress(volatile unsigned *X, const uint32_t * datain); + +#define SHA_F1(X,Y,Z) ((((Y)^(Z))&(X))^(Z)) +#define SHA_F2(X,Y,Z) ((X)^(Y)^(Z)) +#define SHA_F3(X,Y,Z) (((X)&(Y))|((Z)&((X)|(Y)))) +#define SHA_F4(X,Y,Z) ((X)^(Y)^(Z)) + +#define SHA_MIX(n,a,b,c) XW(n) = SHA_ROTL(XW(a)^XW(b)^XW(c)^XW(n), 1) + +SHA1Sum::SHA1Sum() : size(0), mDone(false) +{ + // Initialize H with constants from FIPS180-1. + H[0] = 0x67452301L; + H[1] = 0xefcdab89L; + H[2] = 0x98badcfeL; + H[3] = 0x10325476L; + H[4] = 0xc3d2e1f0L; +} + +/* Explanation of H array and index values: + * The context's H array is actually the concatenation of two arrays + * defined by SHA1, the H array of state variables (5 elements), + * and the W array of intermediate values, of which there are 16 elements. + * The W array starts at H[5], that is W[0] is H[5]. + * Although these values are defined as 32-bit values, we use 64-bit + * variables to hold them because the AMD64 stores 64 bit values in + * memory MUCH faster than it stores any smaller values. + * + * Rather than passing the context structure to shaCompress, we pass + * this combined array of H and W values. We do not pass the address + * of the first element of this array, but rather pass the address of an + * element in the middle of the array, element X. Presently X[0] is H[11]. + * So we pass the address of H[11] as the address of array X to shaCompress. + * Then shaCompress accesses the members of the array using positive AND + * negative indexes. + * + * Pictorially: (each element is 8 bytes) + * H | H0 H1 H2 H3 H4 W0 W1 W2 W3 W4 W5 W6 W7 W8 W9 Wa Wb Wc Wd We Wf | + * X |-11-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 | + * + * The byte offset from X[0] to any member of H and W is always + * representable in a signed 8-bit value, which will be encoded + * as a single byte offset in the X86-64 instruction set. + * If we didn't pass the address of H[11], and instead passed the + * address of H[0], the offsets to elements H[16] and above would be + * greater than 127, not representable in a signed 8-bit value, and the + * x86-64 instruction set would encode every such offset as a 32-bit + * signed number in each instruction that accessed element H[16] or + * higher. This results in much bigger and slower code. + */ +#define H2X 11 /* X[0] is H[11], and H[0] is X[-11] */ +#define W2X 6 /* X[0] is W[6], and W[0] is X[-6] */ + +/* + * SHA: Add data to context. + */ +void SHA1Sum::update(const uint8_t *dataIn, uint32_t len) +{ + MOZ_ASSERT(!mDone); + register unsigned int lenB; + register unsigned int togo; + + if (!len) + return; + + /* accumulate the byte count. */ + lenB = (unsigned int)(size) & 63U; + + size += len; + + /* + * Read the data into W and process blocks as they get full + */ + if (lenB > 0) { + togo = 64U - lenB; + if (len < togo) + togo = len; + memcpy(u.b + lenB, dataIn, togo); + len -= togo; + dataIn += togo; + lenB = (lenB + togo) & 63U; + if (!lenB) { + shaCompress(&H[H2X], u.w); + } + } + while (len >= 64U) { + len -= 64U; + shaCompress(&H[H2X], (uint32_t *)dataIn); + dataIn += 64U; + } + if (len) { + memcpy(u.b, dataIn, len); + } +} + + +/* + * SHA: Generate hash value + */ +void SHA1Sum::finish(uint8_t hashout[20]) +{ + MOZ_ASSERT(!mDone); + register uint64_t size2 = size; + register uint32_t lenB = (uint32_t)size2 & 63; + + static const uint8_t bulk_pad[64] = { 0x80,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }; + + /* + * Pad with a binary 1 (e.g. 0x80), then zeroes, then length in bits + */ + + update(bulk_pad, (((55+64) - lenB) & 63) + 1); + MOZ_ASSERT(((uint32_t)size & 63) == 56); + /* Convert size from bytes to bits. */ + size2 <<= 3; + u.w[14] = SHA_HTONL((uint32_t)(size2 >> 32)); + u.w[15] = SHA_HTONL((uint32_t)size2); + shaCompress(&H[H2X], u.w); + + /* + * Output hash + */ + u.w[0] = SHA_HTONL(H[0]); + u.w[1] = SHA_HTONL(H[1]); + u.w[2] = SHA_HTONL(H[2]); + u.w[3] = SHA_HTONL(H[3]); + u.w[4] = SHA_HTONL(H[4]); + memcpy(hashout, u.w, 20); + mDone = true; +} + +/* + * SHA: Compression function, unrolled. + * + * Some operations in shaCompress are done as 5 groups of 16 operations. + * Others are done as 4 groups of 20 operations. + * The code below shows that structure. + * + * The functions that compute the new values of the 5 state variables + * A-E are done in 4 groups of 20 operations (or you may also think + * of them as being done in 16 groups of 5 operations). They are + * done by the SHA_RNDx macros below, in the right column. + * + * The functions that set the 16 values of the W array are done in + * 5 groups of 16 operations. The first group is done by the + * LOAD macros below, the latter 4 groups are done by SHA_MIX below, + * in the left column. + * + * gcc's optimizer observes that each member of the W array is assigned + * a value 5 times in this code. It reduces the number of store + * operations done to the W array in the context (that is, in the X array) + * by creating a W array on the stack, and storing the W values there for + * the first 4 groups of operations on W, and storing the values in the + * context's W array only in the fifth group. This is undesirable. + * It is MUCH bigger code than simply using the context's W array, because + * all the offsets to the W array in the stack are 32-bit signed offsets, + * and it is no faster than storing the values in the context's W array. + * + * The original code for sha_fast.c prevented this creation of a separate + * W array in the stack by creating a W array of 80 members, each of + * whose elements is assigned only once. It also separated the computations + * of the W array values and the computations of the values for the 5 + * state variables into two separate passes, W's, then A-E's so that the + * second pass could be done all in registers (except for accessing the W + * array) on machines with fewer registers. The method is suboptimal + * for machines with enough registers to do it all in one pass, and it + * necessitates using many instructions with 32-bit offsets. + * + * This code eliminates the separate W array on the stack by a completely + * different means: by declaring the X array volatile. This prevents + * the optimizer from trying to reduce the use of the X array by the + * creation of a MORE expensive W array on the stack. The result is + * that all instructions use signed 8-bit offsets and not 32-bit offsets. + * + * The combination of this code and the -O3 optimizer flag on GCC 3.4.3 + * results in code that is 3 times faster than the previous NSS sha_fast + * code on AMD64. + */ +static void +shaCompress(volatile unsigned *X, const uint32_t *inbuf) +{ + register unsigned A, B, C, D, E; + + +#define XH(n) X[n-H2X] +#define XW(n) X[n-W2X] + +#define K0 0x5a827999L +#define K1 0x6ed9eba1L +#define K2 0x8f1bbcdcL +#define K3 0xca62c1d6L + +#define SHA_RND1(a,b,c,d,e,n) \ + a = SHA_ROTL(b,5)+SHA_F1(c,d,e)+a+XW(n)+K0; c=SHA_ROTL(c,30) +#define SHA_RND2(a,b,c,d,e,n) \ + a = SHA_ROTL(b,5)+SHA_F2(c,d,e)+a+XW(n)+K1; c=SHA_ROTL(c,30) +#define SHA_RND3(a,b,c,d,e,n) \ + a = SHA_ROTL(b,5)+SHA_F3(c,d,e)+a+XW(n)+K2; c=SHA_ROTL(c,30) +#define SHA_RND4(a,b,c,d,e,n) \ + a = SHA_ROTL(b,5)+SHA_F4(c,d,e)+a+XW(n)+K3; c=SHA_ROTL(c,30) + +#define LOAD(n) XW(n) = SHA_HTONL(inbuf[n]) + + A = XH(0); + B = XH(1); + C = XH(2); + D = XH(3); + E = XH(4); + + LOAD(0); SHA_RND1(E,A,B,C,D, 0); + LOAD(1); SHA_RND1(D,E,A,B,C, 1); + LOAD(2); SHA_RND1(C,D,E,A,B, 2); + LOAD(3); SHA_RND1(B,C,D,E,A, 3); + LOAD(4); SHA_RND1(A,B,C,D,E, 4); + LOAD(5); SHA_RND1(E,A,B,C,D, 5); + LOAD(6); SHA_RND1(D,E,A,B,C, 6); + LOAD(7); SHA_RND1(C,D,E,A,B, 7); + LOAD(8); SHA_RND1(B,C,D,E,A, 8); + LOAD(9); SHA_RND1(A,B,C,D,E, 9); + LOAD(10); SHA_RND1(E,A,B,C,D,10); + LOAD(11); SHA_RND1(D,E,A,B,C,11); + LOAD(12); SHA_RND1(C,D,E,A,B,12); + LOAD(13); SHA_RND1(B,C,D,E,A,13); + LOAD(14); SHA_RND1(A,B,C,D,E,14); + LOAD(15); SHA_RND1(E,A,B,C,D,15); + + SHA_MIX( 0, 13, 8, 2); SHA_RND1(D,E,A,B,C, 0); + SHA_MIX( 1, 14, 9, 3); SHA_RND1(C,D,E,A,B, 1); + SHA_MIX( 2, 15, 10, 4); SHA_RND1(B,C,D,E,A, 2); + SHA_MIX( 3, 0, 11, 5); SHA_RND1(A,B,C,D,E, 3); + + SHA_MIX( 4, 1, 12, 6); SHA_RND2(E,A,B,C,D, 4); + SHA_MIX( 5, 2, 13, 7); SHA_RND2(D,E,A,B,C, 5); + SHA_MIX( 6, 3, 14, 8); SHA_RND2(C,D,E,A,B, 6); + SHA_MIX( 7, 4, 15, 9); SHA_RND2(B,C,D,E,A, 7); + SHA_MIX( 8, 5, 0, 10); SHA_RND2(A,B,C,D,E, 8); + SHA_MIX( 9, 6, 1, 11); SHA_RND2(E,A,B,C,D, 9); + SHA_MIX(10, 7, 2, 12); SHA_RND2(D,E,A,B,C,10); + SHA_MIX(11, 8, 3, 13); SHA_RND2(C,D,E,A,B,11); + SHA_MIX(12, 9, 4, 14); SHA_RND2(B,C,D,E,A,12); + SHA_MIX(13, 10, 5, 15); SHA_RND2(A,B,C,D,E,13); + SHA_MIX(14, 11, 6, 0); SHA_RND2(E,A,B,C,D,14); + SHA_MIX(15, 12, 7, 1); SHA_RND2(D,E,A,B,C,15); + + SHA_MIX( 0, 13, 8, 2); SHA_RND2(C,D,E,A,B, 0); + SHA_MIX( 1, 14, 9, 3); SHA_RND2(B,C,D,E,A, 1); + SHA_MIX( 2, 15, 10, 4); SHA_RND2(A,B,C,D,E, 2); + SHA_MIX( 3, 0, 11, 5); SHA_RND2(E,A,B,C,D, 3); + SHA_MIX( 4, 1, 12, 6); SHA_RND2(D,E,A,B,C, 4); + SHA_MIX( 5, 2, 13, 7); SHA_RND2(C,D,E,A,B, 5); + SHA_MIX( 6, 3, 14, 8); SHA_RND2(B,C,D,E,A, 6); + SHA_MIX( 7, 4, 15, 9); SHA_RND2(A,B,C,D,E, 7); + + SHA_MIX( 8, 5, 0, 10); SHA_RND3(E,A,B,C,D, 8); + SHA_MIX( 9, 6, 1, 11); SHA_RND3(D,E,A,B,C, 9); + SHA_MIX(10, 7, 2, 12); SHA_RND3(C,D,E,A,B,10); + SHA_MIX(11, 8, 3, 13); SHA_RND3(B,C,D,E,A,11); + SHA_MIX(12, 9, 4, 14); SHA_RND3(A,B,C,D,E,12); + SHA_MIX(13, 10, 5, 15); SHA_RND3(E,A,B,C,D,13); + SHA_MIX(14, 11, 6, 0); SHA_RND3(D,E,A,B,C,14); + SHA_MIX(15, 12, 7, 1); SHA_RND3(C,D,E,A,B,15); + + SHA_MIX( 0, 13, 8, 2); SHA_RND3(B,C,D,E,A, 0); + SHA_MIX( 1, 14, 9, 3); SHA_RND3(A,B,C,D,E, 1); + SHA_MIX( 2, 15, 10, 4); SHA_RND3(E,A,B,C,D, 2); + SHA_MIX( 3, 0, 11, 5); SHA_RND3(D,E,A,B,C, 3); + SHA_MIX( 4, 1, 12, 6); SHA_RND3(C,D,E,A,B, 4); + SHA_MIX( 5, 2, 13, 7); SHA_RND3(B,C,D,E,A, 5); + SHA_MIX( 6, 3, 14, 8); SHA_RND3(A,B,C,D,E, 6); + SHA_MIX( 7, 4, 15, 9); SHA_RND3(E,A,B,C,D, 7); + SHA_MIX( 8, 5, 0, 10); SHA_RND3(D,E,A,B,C, 8); + SHA_MIX( 9, 6, 1, 11); SHA_RND3(C,D,E,A,B, 9); + SHA_MIX(10, 7, 2, 12); SHA_RND3(B,C,D,E,A,10); + SHA_MIX(11, 8, 3, 13); SHA_RND3(A,B,C,D,E,11); + + SHA_MIX(12, 9, 4, 14); SHA_RND4(E,A,B,C,D,12); + SHA_MIX(13, 10, 5, 15); SHA_RND4(D,E,A,B,C,13); + SHA_MIX(14, 11, 6, 0); SHA_RND4(C,D,E,A,B,14); + SHA_MIX(15, 12, 7, 1); SHA_RND4(B,C,D,E,A,15); + + SHA_MIX( 0, 13, 8, 2); SHA_RND4(A,B,C,D,E, 0); + SHA_MIX( 1, 14, 9, 3); SHA_RND4(E,A,B,C,D, 1); + SHA_MIX( 2, 15, 10, 4); SHA_RND4(D,E,A,B,C, 2); + SHA_MIX( 3, 0, 11, 5); SHA_RND4(C,D,E,A,B, 3); + SHA_MIX( 4, 1, 12, 6); SHA_RND4(B,C,D,E,A, 4); + SHA_MIX( 5, 2, 13, 7); SHA_RND4(A,B,C,D,E, 5); + SHA_MIX( 6, 3, 14, 8); SHA_RND4(E,A,B,C,D, 6); + SHA_MIX( 7, 4, 15, 9); SHA_RND4(D,E,A,B,C, 7); + SHA_MIX( 8, 5, 0, 10); SHA_RND4(C,D,E,A,B, 8); + SHA_MIX( 9, 6, 1, 11); SHA_RND4(B,C,D,E,A, 9); + SHA_MIX(10, 7, 2, 12); SHA_RND4(A,B,C,D,E,10); + SHA_MIX(11, 8, 3, 13); SHA_RND4(E,A,B,C,D,11); + SHA_MIX(12, 9, 4, 14); SHA_RND4(D,E,A,B,C,12); + SHA_MIX(13, 10, 5, 15); SHA_RND4(C,D,E,A,B,13); + SHA_MIX(14, 11, 6, 0); SHA_RND4(B,C,D,E,A,14); + SHA_MIX(15, 12, 7, 1); SHA_RND4(A,B,C,D,E,15); + + XH(0) += A; + XH(1) += B; + XH(2) += C; + XH(3) += D; + XH(4) += E; +} |